The
bottlenose dolphin is one of the most well known marine mammals. With
their friendly and curious nature and their adaptability to captivity,
these animals have a long relationship with humans. Tursiops truncatus
(more commonly known as Bottlenose Dolphins) are cetaceans belonging to
the suborder Odontoceti. The largest of the oceanic Dolphins, they live
up to 30 years in many of the coastal waters of the world, from cold temperate
to tropical waters.Although the largest Bottlenose Dolphins are twelve
feet long and weigh 1400 pounds, most are significantly smaller. These
animals are characterized by a long beak-like snout, a pair of broad flippers
which are slightly pointed, a large, rounded melon on their heads, and
the dolphin "smile"--really caused by the arrangement of facial muscles
and not by any emotional state. This smile contains over fifty sharp conical
teeth, used to grab food. They aren’t needed for chewing, since the bottlenose
dolphin swallows its food whole.

A
single blowhole is the dolphin’s only method of respiration. Typically,
a bottlenose dolphin will surface every two minutes for air, although
they can go longer without breathing during their deepest dives (of up
to 1,000 feet or more). The melon on the dolphin’s head is mainly made
up of fatty tissue and is part of the animal’s hearing apparatus. The
Dolphin’s small outer ear is primarily used for hearing when the head
is above water--underwater sound is carried through the melon.

Sound
is extremely important to the bottlenose dolphin, since they use echolocation
to navigate. To echolocate off a target, a Dolphin bounces sound--usually
a click--off a distant target and uses the echo to figure out where the
target is. That target can be prey, a predator, or an obstacle. Sound
is also important in dolphin communications. They use single pitched "whistles"
to locate each other and broadcast their location. This is especially
important if a baby dolphin becomes separated from its mother.

Dolphins
are extremely social animals. Pods of two to 12 dolphins make up family
units, although the makeup of these groups can change over time. Some
dolphins seem to live without a pod, never interacting with other dolphins.
No one knows if these dolphins leave by choice or are forced out. Young
male dolphins typically leave their mother’s pod at puberty, forming a
new group with other young males. These male dolphins will then establish
dominance within their new groups. The most dominant animals get the first
choice of mates and first chance to eat when food is discovered. In their
struggles for dominance, male dolphins will engage in chasing, ramming,
biting and slapping.

Despite
its many teeth, a dolphin’s prey is small enough to swallow whole. Typical
animals in a bottlenose dolphin diet include small fish, shrimp, eels,
catfish, mullet, and squid. Like many other cetaceans, dolphins are cooperative
hunters, herding fish and trapping them between pod members. Dolphin pods
can even drive schools of fish onto mud flats where pod members can temporarily
strand themselves to catch them. Dolphins have even been known to help
humans herd a school of fish for mutual benefit. Since hunting techniques
seem to vary greatly between pods of dolphins, scientists think that adult
dolphins teach the young how to hunt starting at a very early age.

There
is no doubt that dolphins are highly intelligent animals. Captive dolphins
can learn to understand a language of hand signals including basic grammatical
ideas such as nouns and verbs. Dolphins in captivity are easily trained
to execute simple tasks for humans and to perform for their entertainment.
The complexities of dolphin behavior in the wild, however, remain a mystery.